Rust from side bars

[jonnysouth]

Fitting a new set of side bars after removing an old set which have been on a few years and now very corroded, noticed at least one of the holes on the underside of the van has damage to the paint and some rust. Any ideas on the best way to treat this? Don't want to just fit the new brackets and store up issues for future.
Thanks

 

[Dellmassive]

Back in the old days, I used a rust converter like this.

Then painted over to stop further issue's... IE a touchup pen.

Can't see why that wouldn't work here?

https://amzn.to/38Z2w6W

.




.

 

[Dellmassive]

The T6 body is made from Steel....which will rust.

But they dip the shell to give it a galvanized coating..... Which won't rust.

So anytime the galvanized coating is penitrated by a scratch, cut or drill hole to expose the underlying steel..... Rust can start to form.

 

[Skyliner33]

The T6 body is made from Steel....which will rust.

But they dip the shell to give it a galvanized coating..... Which won't rust.

So anytime the galvanized coating is penitrated by a scratch, cut or drill hole to expose the underlying steel..... Rust can start to form.

In theory galvanising (zinc coating) should still prevent the steel from rusting, even if the layer of zinc becomes scratched, by sacrificial protection as zinc is more reactive than iron. I fact on ships they bolt sacrificial anodes of zinc (or aluminium) onto the hull. These are replaced after they have oxidised away, this protects the hull. You can see them on this picture.

Not sure why its not so effective for VW :/

 

[Dellmassive]

Maybe so....

But in reality rust forms on the exposed steel....

Drilling holes through the bodywork for cable runs.

And screwing down ply lining are prime example s.

When someone gets a van, then removes the ply and screws...to do a conversion.... If the screw holes are not treated ...... They will rust.... You can see it from underneath the van all the time.

I hate the fact that the ply liner people screw through the vans floor to the exposed world under the van.....

Then there is the reaction between dis similar metals . . ..

Oh jeez.... It keeps me awake at night..


I remember reading a comment on the towbar thread where a ply lining fitter had used screws so long then went right through the spare wheel plastic liner under the van !!!!

 

[jonnysouth]

Thanks, I wire brushed the rusted part back and seemed to be pretty much just on the surface and once cleaned off hole edge and surrounding steel seems to be very sound so gave it a good coat of hammerite (going to do a 2nd coat to cover any bits I missed as pretty tricky painting it on upside down). Not too worried about the black/finish as going to be covered by the brackets and plastic under trays.
I think should give me some protection in future.
Now wondering if I should do anything with the new bolts before fitting, the ones I removed where well rusted and I'm thinking could be a cause of the issue. Have done a bit of research on corrosion inhibitors from WD40 and GT85 which I have to hand to more specialist bike/auto stuff which I'd have to order, not sure if any will make much difference over a few years but want to avoid issues in future if possible. Any suggestions? Has anyone else treated these or just fitted as they come?

 

[jonnysouth]

New and old fixings, all of the old bolts sheared rather than undo.